Common Etiologies and Clinical Significance of Gastric Intraepithelial Lymphocytosis

Abstract

Abstract Background Increased intraepithelial lymphocytes or intraepithelial lymphocytosis (IEL) in the upper gastrointestinal (GI) tract is a response to various mucosal injury. However, the frequency of gastric IEL in GI tract biopsy is not well documented, and the etiologies of gastric IEL are yet to be defined. Methods Cases with a diagnosis of “intraepithelial lymphocytosis” and “intraepithelial lymphocytes” were retrieved from 25,074 GI biopsies and 8,921 partial gastrectomies in our departmental database (Powerpath) for a 1-year period. The diagnosis of IEL was confirmed by the report and/or slide review. Possible etiology or causes of gastric IEL were investigated by correlation with clinical information from LIS (EPIC). Results A total of 694 cases with IEL were identified from 33,995 GI tract specimens (biopsy and resection). Among 694 cases, 34 (4.89%) were gastric biopsy and resection cases with IEL, whereas 561 (80.8%), 37 (5.3%), and 62 (8.9%) were duodenal, esophageal, and colonic specimens, respectively. Thirty-four gastric cases with IEL were closely associated with morbid obesity (8, 23.5%), H pylori infection (8, 23.5%), celiac disease (5, 14.7%), lymphocytic gastritis (5, 14.7%), nonspecific gastritis (4, 11.4%), inflammatory bowel disease (3, 8.8%), and gastroesophageal reflux disease (1, 1.9%). Seventeen of 34 (50%) cases had IEL in both gastric and duodenal mucosa. Those 17 cases with gastroduodenal IEL had morbid obesity (n = 5), celiac disease (n = 5), lymphocytic colitis (n = 2), inflammatory bowel disease (n = 2), H pylori gastritis (n = 2), and nonspecific gastritis (n = 1). Five patients with a diagnosis of lymphocytic gastritis were treated with a protein pump inhibitor after pathologic diagnosis. Among them, 4 had a followed-up endoscopy in 12 months, and 3 of them showed persistent IEL in a follow-up biopsy. Conclusion Gastric IEL is less common than duodenal IEL. It is associated with a broad differential diagnosis. Follow-up biopsy may be necessary for some types of gastric IEL. Persistent IEL in follow-up biopsy may be suggestive of a different etiology or requires different treatment strategy.